1. Technical Field
The present invention relates to a flow path member, a liquid ejecting head and a liquid ejecting apparatus.
2. Related Art
As a liquid ejecting apparatus ejecting liquid from a nozzle of a liquid ejecting head to a target, for example, an ink jet type recording apparatus (hereinafter, simply referred to as “a recording apparatus”) ejecting ink droplets from a nozzle of an ink jet type recording head (hereinafter, simply referred to as “a recording head”) is well known.
The recording head is configured of a head body ejecting a ink and a flow path member to which the ink is supplied from an ink reservoir unit such as an ink cartridge and through which the ink is supplied to the head body. The flow path member has, for example, a pressure adjustment unit adjusting the pressure of the ink to be supplied to the head body to be in a predetermined range.
The pressure adjustment unit is configured in such a manner that for example, a pressure chamber is formed by sealing an opening of a groove-shaped flow path with a film and a communication path communicating with the pressure chamber is opened and closed by a valve body due to pressure variation in the pressure chamber (see JP-A-2008-230196).
The valve body has a seal member coming in contact with an opening edge of the communication path. The communication path may be reliably closed using the valve body with the seal member.
However, whenever the valve body opens and closes the communication path due to the pressure variation in the pressure chamber, the ink is gradually accumulated on the opening edge of the communication path. When the accumulation of the ink progresses, the opening-closing operation of the valve body is unstable. For example, the opening degree of the valve body is varies according to an accumulation amount of the ink, even though the same degree of pressure variation occurs in the pressure chamber. Thus, the supply of the ink to the head body is unstable, ejection characteristics of the ink vary and then printing quality is degraded. In addition, when the accumulation of the ink progresses further, sealing by the seal member may be incomplete, even in a state where the valve body closes the communication path. In this case, there is concern that the ink may be ejected from the nozzle of the head body at an unintended timing.
In addition, the problem described above is not limited to the flow path member for the ink jet type recording head and similarly exists in a flow path member which supplies liquid other than the ink to another member. In addition, the problem described above is not limited to the ink jet type recording head and similarly exists in a liquid ejecting head and a liquid ejecting apparatus ejecting the liquid other than the ink.